JP3571439B2 - Coating device - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a coating apparatus that applies a coating liquid to a glass substrate or the like of a color filter for LCD.
[0002]
[Problems to be solved by the invention]
In general, a spin coating method is often used as a method of applying a coating liquid to a large glass substrate such as a color filter for an LCD.
[0003]
This spin coating method includes an open air type and a closed cup type, but both methods have drawbacks in that the coating efficiency is as low as about 10% and the coating film thickness in the corner portion of the substrate becomes too thick. As the size of the substrate is expected to increase in the future, problems have been pointed out with respect to the use amount of the coating solution, the film thickness distribution, the throughput, and the like.
[0004]
As a method for solving the above-mentioned drawbacks of the spin coating method, there are a knife coating method, a roll coating method, and a die coating method.
[0005]
In each of these methods, a coating clearance is provided on a substrate to be coated, and the coating film thickness is determined by the set value to obtain the smoothness of the coating surface. It is difficult to obtain a uniform film thickness when the degree (degree of unevenness) is lower than the coating accuracy (the degree of unevenness is large).
[0006]
A dip coating method is generally known as a method of applying a coating liquid that is not easily affected by unevenness on the substrate surface. However, in this method, it is essential to cover a non-coated portion, and the operation is complicated. It becomes.
[0007]
A method similar to the principle of the dip coating method and a method of selectively applying the coating liquid only to the main surface of the substrate is described in Yuji Ozaki of Sogo Gijutsu Center (April 30, 1988). A coating method of a coating liquid described on page 336 of the book "Advances in Latest Coating Technology" is known.
[0008]
In this method, a coating liquid is supplied in a substantially horizontal direction from a die head or a slide die, and the base is relatively vertically moved to a position close to a die lip formed on a side surface of the die head or the slide die. The coating liquid supplied from the die head or the slide die forms a bead between the base and the die lip, and is applied to the main surface of the base as the base moves upward to form a coating film.
[0009]
This coating method is generally used as a coating method for a continuous substrate. The thickness of the applied coating liquid is determined by the relative speed between the substrate and the coating head and the viscosity of the coating liquid. That is, since the coating liquid pulled up from the bead formed between the base and the die lip falls along the base under the influence of gravity, the film is formed by a balance between the speed of the drop and the speed at which the base pulls up the coating liquid. The thickness is determined.
[0010]
In this coating method, when the coating liquid has low viscosity and low surface tension, it is difficult to form a bead in the clearance provided between the base and the coating head, and the coating liquid is supplied. Immediately after, it may fall by gravity without forming a bead. To prevent this, there is a problem that the clearance between the base and the coating head must be made extremely small.
[0011]
However, when the substrate has low flatness like a glass substrate for an LCD color filter and has irregularities as large as 100 μm, a difference occurs in the tensile force generated when the coating liquid is pulled up from the bead, and the beads have various different characteristics. Shear force will act. When a different shearing force acts locally on the bead as described above, the amount of the coating liquid drawn out from the bead is not uniform, and thus the film thickness is not uniform.
[0012]
Furthermore, in this coating method, even though the coating liquid can be continuously applied to the main surface of the base, the main surface of the base is vertical and the coating liquid is supplied from a direction perpendicular to the base. When applying a coating liquid to a plurality of discontinuous substrates such as a single-wafer substrate, the coating liquid remaining in the bead drops by gravity when the rearmost end of the substrate in the sliding direction passes through the bead. In addition, contamination may be caused by adhering to the tip of the substrate to be coated next, the back surface thereof, and the lower part of the coating head. For this reason, this coating method is unsuitable for use in coating a single-wafer substrate.
[0013]
The coating method using a slide die also has the same disadvantages as the coating method using the die head described above. In particular, in the coating method using the slide die, since the coating liquid flows freely on the inclined surface of the slide die to form a bead between the slide die and the surface of the base, the supply of the coating liquid is stopped at any time. It is difficult to apply the coating liquid continuously to a discontinuous substrate such as a single-wafer substrate.
[0014]
Therefore, there has been proposed a coating apparatus capable of solving the drawbacks in the respective coating methods as described above and forming a uniform coating film in a stable state on a single-wafer substrate without being affected by the physical properties of the coating liquid. (Japanese Unexamined Patent Publication No. 5-146775).
[0015]
As shown in FIG. 10, this coating device is a linear coating device that is attached between a pair of support frames 1A of the device main body 1 in a state where the downstream end in the sliding direction of the substrate S is inclined to be higher. A guide frame 2, a substrate holder 3 slidably attached to the guide frame 2, and a linear slit 4 a that opens upward, and the slit 4 a extends in a direction orthogonal to the axial direction of the guide frame 2. And a coating head 4 disposed below the guide frame 2.
[0016]
The substrate holder 3 is screwed to a ball screw 5 provided along the guide frame 2, and is slid along the guide frame 2 by rotating the ball screw 5 by the motor M. The substrate S is sucked and held on the downward suction surface thereof by the operation of a suction mechanism (not shown) connected to the suction pipe connecting portion 3A. The coating head 4 discharges the coating liquid supplied from a coating liquid supply mechanism (not shown) upward from the slit 4a.
[0017]
FIG. 11 shows a state of the coating apparatus at the start of coating, in which the substrate S sucked on the suction surface of the substrate holder 3 has its tip end immediately above the slit 4 a of the coating head 4 via a predetermined clearance. And are opposed to each other.
[0018]
When the coating liquid R is supplied to the coating head 4 from the coating liquid supply mechanism, the supplied coating liquid R is discharged from the slit 4a to form a bead B as shown in an enlarged view in FIG. It adheres to the lower surface of the tip of the substrate S. At this time, the minimum clearance C1 between the opening of the slit 4a and the lower surface of the substrate S adsorbed on the substrate holder 3 is such that the viscosity and surface tension of the coating liquid R do not leak out of the bead B. It is set in consideration of physical properties such as.
[0019]
12, a meniscus L1 is formed on the rear end side (left side in the figure) of the substrate S of the bead B and a meniscus L2 is formed on the front end side (right side in the figure). The height dimension h1 of the meniscus L1 and the meniscus The height dimension h2 of L2 has a relationship of h1 <h2 because the guide frame 2 is inclined at the angle θ.
[0020]
When the motor M is driven from the state of FIG. 11 and the ball screw 5 is rotated, the substrate holder 3 is slid obliquely upward along the guide frame 2 at a constant speed.
[0021]
Thus, as shown in FIGS. 13 and 14, the coating liquid R is sequentially adhered from the bead B to the lower surface of the substrate S, and a layer Ra of the coating liquid R is formed. At this time, the application liquid R is continuously supplied to the application head 4, and the amount of the application liquid R in the bead B is kept constant.
[0022]
Then, as shown in FIG. 15, when the substrate S rises along the guide frame 2 and the rear end S2 reaches the slit 4a of the coating head 4, the slide of the substrate holder 3 is stopped, and the coating head is further moved. The application liquid R forming the bead B is sucked into the coating head 4 by the operation of the suckback valve (not shown) connected to the nozzle 4, and the bead B disappears. Thereby, the coating head 4 and the layer Ra of the coating liquid R on the substrate S are separated.
[0023]
Thereafter, the substrate S is removed from the substrate holder 3, held horizontally in an upward or downward state, conveyed to a drying unit (not shown), dried by means such as a far-infrared heater, and dried on the main surface of the substrate S. A coating film having a uniform thickness is formed.
[0024]
In general, the main surface of a glass substrate for an LCD color filter has low smoothness, and usually has irregularities of 50 to 70 μm, and at most about 100 μm. In addition, by maintaining a sufficiently large clearance of 10 to 1000 times, preferably 20 times or more with respect to the thickness of the layer Ra formed on the substrate S, it is possible to reduce the influence of the unevenness of the main surface of the substrate S. it can. Furthermore, since the application of the coating liquid to the substrate S is performed in a state where the substrate S is inclined (5 to 20 degrees, preferably 11 degrees), the lower the coating liquid applied along the main surface of the substrate S , Whereby the surface of the coating film can be smoothed.
[0025]
However, when the coating liquid is continuously applied to the single-wafer substrate by the above-described conventional coating apparatus, after the application of the coating liquid to one substrate S is completed, the substrate holder 3 is turned over and the substrate S is sucked. Is released and the substrate S is removed. Then, a new substrate S is adsorbed and set on the substrate holder 3, and the substrate holder 3 is slid along the guide frame 2 in the direction opposite to the direction of the application of the application liquid to be applied. It is necessary to return to the starting position.
[0026]
For this reason, the processing time per substrate becomes long, and the processing is limited to about 30 substrates / hour at the maximum.
[0027]
The present invention has been made in view of such circumstances, and it is possible to form a smooth and uniform coating film on a single-wafer substrate without being affected by the physical properties of a coating solution, and to perform a unit time. It is an object of the present invention to provide a coating apparatus capable of increasing the number of processed sheets per hit.
[0028]
[Means for Solving the Problems]
In order to achieve the above object, a coating apparatus according to a first aspect of the present invention includes a coating head having a strip-shaped slit which opens upward and extends in a horizontal direction, and a substrate on which a coating liquid is coated is provided above the coating head. A substrate holding member for holding the substrate in an inclined state and in parallel with the application head, supplying the application liquid to the application head, and discharging from the slit of the application head between the application head and the substrate held by the substrate holding member. A bead is formed by a coating liquid, and the substrate and the coating are relatively moved in opposite directions, and the coating liquid is applied to the substrate by applying the coating liquid to the coating liquid application surface of the substrate from the bead. In the coating apparatus, the coating head reciprocates along a coating head guide member that is inclined in a direction orthogonal to the band-shaped slit extending in the horizontal direction of the coating head and in an upward direction. A substrate guide member is disposed above the coating head guide member and extends in a direction perpendicular to the coating head guide member and horizontally. Two sliders are arranged on the substrate guide member along the substrate guide member. The two sliders are alternately positioned above the coating head guide member, and the substrate holding member holds the substrates respectively held by the two sliders. Positioning the substrate at a first position where the coating liquid application surface is directed downward and parallel to the moving direction of the coating head, and at a second position where the substrate is positioned such that the coating liquid application surface is directed upward and horizontally. It was configured to be freely attached.
[0029]
In the coating apparatus according to the first aspect, when one of the sliders, in which the substrate holding member holding the substrate is positioned at the first position, is positioned above the coating head guide member, the coating head moves along the coating head guide member. And slides linearly in an obliquely upward direction while facing the application surface of the substrate.
[0030]
At this time, the coating liquid is continuously supplied to the coating head, and the coating liquid is discharged upward from the slit to form a bead of the coating liquid between the coating head and the coating surface of the substrate facing the coating head.
[0031]
Then, with the slide of the coating head, the coating liquid is sequentially adhered from the bead to the surface of the substrate to be coated, and a layer of the coating liquid is formed on the substrate.
[0032]
When the application of the application liquid to the substrate is completed in this manner, after the substrate holding member is positioned at the second position, one of the sliders slides along the substrate guide member and separates from above the application head guide member. Then, instead of this one slider, the other slider in which the substrate holding member holding the substrate is located at the first position is positioned above the coating head guide member, and similarly, the coating head moves obliquely upward. The application of the application liquid to the substrate is performed by the slide.
[0033]
While the application liquid was being applied to the substrate held by the other slider, the application liquid was applied to one of the sliders and held horizontally by the substrate holding member positioned at the second position. The substrate is removed from the substrate holding member and replaced with a new substrate.
[0034]
After the application of the application liquid to the other slider is completed, the one slider whose substrate has been exchanged is replaced with the other slider again, and is positioned above the application head guide member and held thereon. The application liquid is applied to the substrate.
[0035]
As described above, the step of applying the coating liquid to the substrate and the step of replacing the substrate coated with the coating liquid are alternately performed on the two sliders.
[0036]
In order to achieve the above object, a coating apparatus according to a second aspect of the present invention includes a coating head having a strip-shaped slit that opens upward and extends in the horizontal direction, and a substrate on which a coating liquid is coated is provided above the coating head. A substrate holding member for holding the substrate in an inclined state and in parallel with the application head, supplying the application liquid to the application head, and discharging from the slit of the application head between the application head and the substrate held by the substrate holding member. A bead is formed by a coating liquid, and the substrate and the coating are relatively moved in opposite directions, and the coating liquid is applied to the substrate by applying the coating liquid to the coating liquid application surface of the substrate from the bead. In the coating apparatus, the coating head reciprocates along a coating head guide member that is inclined in a direction orthogonal to the band-shaped slit extending in the horizontal direction of the coating head and in an upward direction. A rotating shaft that is inclined upward and rotatable around an axis is disposed above the coating head guide member, and the pair of substrate holding members is symmetrical about the rotating shaft with the rotating shaft interposed therebetween. When the substrate holding member is positioned above the rotation axis with the rotation of the rotation axis, the substrate holding member is positioned in a horizontal state, and when the respective substrate holding members are positioned below the rotation axis, The configuration was such that the held substrate was positioned in a state parallel to the moving direction of the coating head.
[0037]
In the coating apparatus according to the second aspect, when one of the pair of substrate holding members holding the substrate is positioned below the rotation axis with the rotation of the rotation axis, the coating head faces downward along the coating head guide member. The substrate is slid linearly in an obliquely upward direction while facing the application surface of the substrate held on the substrate.
[0038]
At this time, similarly to the first invention, the coating liquid is discharged from the bead formed between the coating surface of the substrate and the coating liquid discharged upward from the slit of the coating head, and the coating liquid is applied to the substrate by sliding the coating head. To form a coating liquid layer on the substrate.
[0039]
When the application of the coating liquid to the substrate held by the one substrate holding member is completed in this way, the rotation shaft is rotated half a turn, and the one substrate holding member holding the substrate coated with the coating liquid is The other substrate holding member that holds the substrate on which the coating liquid is not applied is positioned above the rotation axis below the rotation axis.
[0040]
Then, a coating liquid is applied to the substrate held by the other substrate holding member by the same process. During this time, the substrate, which has been horizontally applied to one of the substrate holding members and has been coated with the application liquid, is removed from the substrate holding member and replaced with a new substrate.
[0041]
After the substrate exchange is completed, the one substrate holding member is replaced with the other substrate holding member by rotating the rotation shaft again by half after the application liquid application process is completed for the other substrate holding member. The application liquid is applied to the substrate, which is located above the application head guide member and is held.
[0042]
As described above, the step of applying the coating liquid to the substrate and the step of replacing the substrate to which the coating liquid has been applied are alternately performed on the pair of substrate holding members.
[0043]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the most preferred embodiment of the present invention will be described.
[0044]
FIG. 1 is a side view showing the coating apparatus 10 according to the first embodiment, and FIG. 2 is a view of the coating apparatus 10 taken along the line II-II in FIG.
[0045]
In FIGS. 1 and 2, a coating device 10 has pivots 11A and 11B attached to both sides of a main body 11 of the device rotatably supported by a gantry F. The main body 11 is rotated about the center and tilted.
[0046]
The rotation center P of the main body 11 is set so as to coincide with the axis centers of holder support shafts 15A and 15B described later.
[0047]
The main body 11 is provided with an upper stage 11C and a lower stage 11D disposed below the upper stage 11C and parallel to the upper stage 11C.
[0048]
A pair of ball screws 12 are mounted on the upper stage 11C so as to extend in parallel with the axes of the support shafts 11A and 11B, with both ends rotatably supported. It is designed to be rotated by a motor.
[0049]
Sliders 13A and 13B are connected to the ball screw 12 by screwing connecting portions 13a and 13b respectively attached to the lower surfaces thereof, and are slid along the ball screw 12 by the rotation of the ball screw 12. It has become so. The sliders 13A and 13B are further guided along the ball screw 12 by a pair of linear guides 14 arranged outside the ball screw 12 and interposed between the sliders 13A and 13B and the upper stage 11C. It has become so.
[0050]
The length of each of the ball screw 12 and the linear guide 14 is set to be slightly longer than the width of three sliders, and the slider 13A and the slider 13B are mutually opposite as shown in FIG. They are arranged adjacent to each other.
[0051]
Holder support shafts 15A and 15B are mounted on the upper surfaces of the sliders 13A and 13B so that both ends thereof are rotatably supported so as to extend in the horizontal direction and in parallel with the axial direction of the ball screw 12. Motors MA and MB are connected to ends of the holder support shafts 15A and 15B, respectively, and the holder support shafts 15A and 15B are rotated by driving the motors MA and MB, respectively.
[0052]
The base ends of the pair of holder support arms 16A, 16B are fixed to the center portions of the holder support shafts 15A, 15B so that the pair of holder support arms 16A, 16B extend in a direction perpendicular to the axial direction of the shafts 15A, 15B. The rotation of the support shafts 15A and 15B allows the upper stage 11C to rotate in a plane perpendicular to the upper stage 11C.
[0053]
Holding plates 17A and 17B for adsorbing and holding the substrate S are attached to the distal ends of the pair of holder support arms 16A and 16B, respectively, at right angles to the axial direction of the holder support arms 16A and 16B. A compressor (not shown) is connected to each of the holding plates 17A and 17B so as to adsorb and hold the substrate S on an adsorption surface formed on each lower surface.
[0054]
Instead of sucking the substrate S by connecting a compressor to the holding plates 17A and 17B, chucks may be attached to four places of the holding plates 17A and 17B, and the substrate S may be held by the chucks.
[0055]
A ball screw 18 is attached to the center of the lower stage 11D so that both ends thereof are rotatably supported so as to extend in a direction orthogonal to the ball screw 12 attached to the upper stage 11C. The screw 18 is adapted to be rotated at a low speed by a drive motor MC connected to its end.
[0056]
The coating head mounting base 20 is connected to the ball screw 18 by screwing a connecting portion 20 a mounted on the lower surface thereof, and is slid along the ball screw 18 by the rotation of the ball screw 18. It has become.
The coating head mounting base 20 is further arranged along the ball screw 18 by a pair of linear guides 21 arranged on both sides of the ball screw 18 and interposed between the coating head mounting base 20 and the lower stage 11D. It is being guided.
[0057]
An elevating mechanism 22 is mounted on the application head mounting base 20. The elevating mechanism 22 has an application head 19 having a linear slit 19a that opens upward, and the slit 19a is positioned in the axial direction of the ball screw 18. It is mounted so as to extend orthogonally and horizontally, and is moved up and down when the lifting mechanism 22 is operated by the motor MD.
[0058]
Also, as shown in FIG. 1, the coating head 19 is used when the coating head mounting base 20 is located at the retracted position (left side in the figure) and the application of the coating liquid to the substrate S described later is started. The application head mounting base 20 is located at the left end side of the drawing of the substrate S held by the holding plate 17A or 17B located at the application position described later, and the application head mounting base 20 is located at the forward position (right side in the drawing). The substrate S is arranged so as to be located on the right end side of the substrate S in the drawing when the application of the application liquid to the substrate S is completed.
[0059]
A coating liquid is supplied to the coating head 19 from a coating liquid supply mechanism described later, and the coating liquid supplied to the coating head 19 is discharged upward from the slit 19a. ing.
[0060]
FIGS. 3 to 6 show examples of the shape of the coating head 19.
[0061]
3 to 6, the main body 19A of the coating head 19 has a length a equal to or larger than the width of the substrate S on which the coating liquid is to be coated, and extends in the center of the upper surface along the axial direction and upward. A slit 19a opening toward the front is formed. A pair of slopes 19B and 19C are formed on both sides of the slit 19a.
[0062]
Inside the main body 19A, there is formed a hollow liquid reservoir 19D extending in parallel with the slit 19a and communicating with the slit 19a over the entire area in the axial direction. A coating liquid supply pipe 19E attached to a lower portion of the slit 19a is connected to the liquid pool 19D, and the coating liquid introduced from the coating liquid supply pipe 19E is discharged from the slit 19a through the liquid pool 19D. It has become.
[0063]
In the drawing, reference numeral 19F denotes a pair of slit length adjusting packings which are detachably fitted to both ends of the slit 19a, respectively, and the slit length adjusting packing 19F has another slit length having a different length. The width of the application liquid discharged from the slit 19a can be adjusted by replacing the packing with an adjustment packing.
[0064]
The dimensions of each part of the coating head 19 shown in the figure are as follows.
[0065]
Length a of main body 19A = 400 mm
Width b of main body 19A = 50 mm
Height c of main body 19A = 80 mm
Length d of slit 19a (width after adjustment by slit length adjusting packing 19F) = 350 mm
The width e of the slit 19a = 2 mm
Depth f of slit 19a = 27mm
The depth g of the sump 19D = 40 mm
As a coating liquid supply mechanism for supplying the coating liquid to the coating head 19, a mechanism as shown in FIG.
[0066]
This coating liquid supply mechanism pushes out the coating liquid contained in the pressurized tank barrel 30 by air pressure supplied through a manual valve 31, and performs a coarse adjustment needle valve 32, a filter 33, a flow meter 34, and a fine adjustment. The ink is supplied to the coating head 19 through the use needle valve 35, the air operated valve 36 and the suck back valve 37.
[0067]
The air actuated valve 36 automatically operates by air pressure when the application of the application liquid onto the substrate S is completed, and stops the supply of the application liquid to the application head 19. The suck-back valve 37 is supplied to the application head 19 by closing the air-operated valve 36 and simultaneously sliding the piston 37a in the direction of the arrow shown in FIG. 7 to generate a negative pressure in the cylinder 37b. The application liquid is sucked and collected.
[0068]
Next, the operation of the coating device will be described.
[0069]
Before the start of coating, the coating device 10 is rotated by a drive mechanism (not shown) around the rotation center P so that the right end in FIG. 1 is directed upward, and the inclination angle is set to a predetermined angle θ. Is done.
[0070]
As shown in FIG. 2, when the slider 13A is positioned at the center of the ball screw 12 by the rotation of the ball screw 12, the slider 13A is positioned on the movement path of the coating head mounting base 20 (hereinafter, referred to as the slider 13A). This position is called a coating position). Then, the slider 13B is displaced from the movement path of the coating head mounting base 20, and is located at the left end of the ball screw 12.
[0071]
When the slider 13A is at the application position, the holder support arm 16A is directed downward, and the holding plate 17A is positioned so as to be parallel to the lower stage 11D. The substrate S is adsorbed and held on the holding plate 17A.
[0072]
Further, the holder support arm 16B of the slider 13B located at a position deviated from the application position is directed upward, and is positioned so that the holding plate 17B is horizontal. Then, while the application liquid is being applied to the substrate S adsorbed on the holding plate 17A, the substrate S is set on the holding plate 17B by a substrate exchange device (not shown).
[0073]
First, the application head mounting base 20 is located at a retracted position (the left side position in FIG. 1, hereinafter referred to as an application start position).
[0074]
In this state, the ball screw 18 is rotated by the drive of the motor MC, and the coating head mounting base 20 is slid at a constant speed from left to right in FIG. 1 at a constant speed, whereby the coating head 19 is held by the holding plate 17A. Is slid in parallel along the lower surface of the substrate S.
[0075]
Almost simultaneously with the start of the sliding of the coating head 19, the supply of the coating liquid to the coating head 19 is started, and the supplied coating liquid is discharged from the slit 19a to form a bead and the bead is formed on the lower surface of the substrate S. Adhere to.
[0076]
Then, as the coating head 19 slides, the coating liquid is sequentially adhered to the lower surface of the substrate S from the beads formed on the coating head 19 to form a layer of the coating liquid.
[0077]
When the coating head mounting base 20 reaches the forward position (the right side position in FIG. 1; hereinafter, referred to as the coating end position), the coating head 19 is disengaged from the rear end of the substrate S, and almost simultaneously with this, the coating head mounting base 20 slides. When stopped, the suck-back valve 37 connected to the coating head 19 is operated, and the coating liquid forming the bead is sucked into the coating head 19 and the bead disappears. Thus, the coating liquid applied to the coating head 19 and the substrate S is separated.
[0078]
The method for applying the coating liquid to the substrate S is the same as the conventional method for applying the coating liquid described with reference to FIGS.
[0079]
As described above, when the application head mounting base 20 reaches the application end position and the application of the application liquid to the substrate S held by the holding plate 17A is completed, the ball screw 18 is rotated reversely by the drive of the motor MC. Then, the application head mounting base 20 is slid in the opposite direction to the above, and returns from the application end position to the application start position.
[0080]
At this time, the application head 19 is lowered by the operation of the elevating mechanism 22, thereby avoiding contact between the application head 19 and the application liquid applied to the lower surface of the substrate S.
[0081]
Thereafter, the motor MA is driven to rotate the holder support shaft 15A and the holder support arm 16A, whereby the holding plate 17A and the substrate S held by the holding plate 17A are moved upward to be in a horizontal state. Is held. At this time, the motor MB of the slider 13B is also driven, and the holder support shaft 15B and the holder support arm 16B are rotated, whereby the holding plate 17B and the substrate S held by the holding plate 17B are moved downward. And is held parallel to the lower stage 11D.
[0082]
Next, while maintaining this state, the ball screw 12 is rotated in the opposite direction, and the sliders 13A and 13B are moved rightward in FIG. Contrary to the above, the slider 13B is located at the application position, and the slider 13A is displaced from the moving path of the application head mounting base 20, and is located at the right end of the ball screw 12.
[0083]
Then, by the same operation as in the case of the substrate S held by the holding plate 17A, the coating head 19 is slid from the coating start position to the coating end position, and the coating liquid is applied to the lower surface of the substrate S held by the holding plate 17B. Applied.
[0084]
While the application liquid is being applied to the substrate S held by the holding plate 17B, the substrate S that has been adsorbed to the holding plate 17A and coated with the coating liquid is held by the substrate exchange device (not shown). 17A, a new substrate S is set instead, and after the application of the application liquid to the substrate S on the slider 13B side is completed, the sliders 13A and 13B are slid in the opposite direction to the above, and the slider 13A is again moved to the application position. The coating liquid is applied to the positioned and held substrate S.
[0085]
As described above, when the application process of the application liquid is performed alternately on the slider 13A side and the slider 13B side, and when the substrate S is exchanged for the holding plate 17B of the slider 13B, the holding plate of the slider 13A is replaced. On the substrate S held on the holding plate 17B of the slider 13B when the replacement of the substrate S on the holding plate 17A of the slider 13A is performed. Since the application of the coating liquid is performed, the application of the coating liquid to the substrate S is always performed. As a result, the number of the substrates S per unit time is twice that of the conventional coating apparatus of FIG. It is possible to apply a coating liquid to the substrate.
[0086]
In the application liquid application step, increasing the slide speed of the application head 19 reduces the thickness of the application liquid layer applied to the substrate S, and conversely, decreasing the slide speed decreases the thickness of the application liquid layer. However, by changing the inclination angle θ of the coating device 10, the thickness of the layer of the coating liquid applied to the substrate S can be changed while keeping the sliding speed of the coating head 19 constant.
[0087]
That is, when the inclination angle θ of the coating device 10 increases, the inclination angle of the substrate S held by the holding plates 17A and 17B also increases, and the thickness of the layer of the coating liquid applied to the substrate S decreases. When the inclination angle θ of the coating apparatus 10 decreases, the inclination angle of the substrate S held by the holding plates 17A and 17B also decreases, and the thickness of the coating liquid applied to the substrate S increases.
[0088]
At this time, since the coating head 19 is also integrally inclined with the inclination of the coating apparatus 10, the relative positional relationship between the coating head 19 and the holding plates 17A and 17B does not change.
[0089]
The single substrate S to which the coating liquid is applied by the coating apparatus 10 is mainly a large glass substrate for an LCD color filter, but the coating liquid can be applied to other substrates in the same manner. The coating liquid can be applied not only to a non-flexible glass substrate but also to a flexible plastic substrate, a metal substrate, or a paper substrate.
[0090]
The coating liquid used in the coating device 10 is mainly a photosensitive resin for drawing a fine pattern on a substrate, but it goes without saying that other coating liquids can be coated. Various coating liquids such as water-based and solvent-based coatings can be used, and further, pigments, dyes, fillers, sensitizers, resins, additives, and the like can be used alone, or several of them can be used. They can be used in combination.
[0091]
FIG. 8 is a side view showing the coating apparatus 40 according to the second embodiment, and FIG. 9 is a view of the coating apparatus 40 taken along line IX-IX in FIG.
[0092]
8 and 9, in the coating apparatus 40, support shafts 41A and 41B attached to both sides of a head mount 41 of the apparatus are rotatably supported by a substrate support mount F '. The head mount 41 is rotated about the and 41B and tilted.
[0093]
Above the head mount 41, the rotating shaft 42 is mounted on the substrate support mount F 'in a state of being inclined in a direction orthogonal to the axial directions of the support shafts 41A and 41B (in a state of being inclined upward to the right in FIG. 8). Both ends are rotatably supported. The bearings at both ends of the rotary shaft 42 are attached to the substrate support gantry F ′ so that the tilt angle of the rotary shaft 42 can be changed. Further, a drive motor (not shown) is connected to one end of the rotary shaft 42, and the rotary shaft 42 is rotated around the drive motor by the drive motor.
[0094]
A pair of holder support arms 43A and 43B are rotatable in a plane including the respective axes and the axis of the rotary shaft 42 at the symmetrical position of the circumferential portion of the intermediate portion of the rotary shaft 42 at the symmetric position of the circumferential portion. The base end is attached. The holder support arms 43A and 43B can be fixed to the rotation shaft 42 at an arbitrary position so as to form a required angle with respect to the rotation shaft 42.
[0095]
The rotation centers of the holder support arms 43A and 43B are set so as to coincide with the rotation center P 'of the head mount 41 when the plane including the axis of the holder support arms 43A and 43B is oriented vertically. .
[0096]
Holding plates 44A and 44B are fixed to the distal ends of the holder support arms 43A and 43B, respectively, at right angles to the axes of the holder support arms 43A and 43B.
[0097]
A compressor (not shown) is connected to each of the holding plates 44A and 44B, as in the case of the coating apparatus in FIGS. 1 and 2, and holds the substrate S by suction on suction surfaces formed on the lower surfaces thereof. Instead of connecting the compressor and sucking the substrate S, chucks may be attached to four positions of the holding plates 44A and 44B, and the chuck may hold the substrate S.
[0098]
A stage 41C is provided on the head mount 41, and the application head 19 is slidably mounted on the stage 41C in a direction orthogonal to the axes of the support shafts 41A and 41B.
[0099]
The structure of the coating head 19 and the structure for sliding the coating head 19 are the same as those of the coating apparatus shown in FIGS. 1 and 2, and are denoted by the same reference numerals as those in FIGS. Further, the application head 19 is connected to an application liquid supply mechanism as shown in FIG. 7, similarly to the application apparatus shown in FIGS.
[0100]
When the coating liquid is applied to the substrate S by the coating device 40, the holder support arm 43A and the holder support arm 43B are rotated around the base end thereof with respect to the rotation shaft 42, and the respective rotations are performed. The angles with respect to the shaft 42 are the same, and when the plane including the axis of the holder support arms 43A and 43B is oriented vertically, the holding plates 44A and 44B located on the upper side are in the horizontal state, respectively. Is set to
[0101]
The angle of the holder support arms 43A, 43B with respect to the rotation shaft 42 is adjusted so that the upper holding plates 44A, 44B are horizontal, as described later. S is exchanged by a substrate exchange device (not shown) in a state where the coating liquid does not flow. However, since the rotating shaft 42 is inclined, the holding plates 44A and 44B located above are set to be horizontal. By doing so, the lower holding plates 44A and 44B are held in a state inclined with respect to the horizontal plane, as can be seen from FIG.
[0102]
The head mount 41 is rotated about the rotation center P ′, so that the head mount 41 extends along the lower surfaces of the holding plates 44A and 44B which are positioned below and held in a state inclined with respect to the horizontal plane as described above. The tilt angle is adjusted so that the coating head 19 slides in parallel.
[0103]
The lower surface of the holding plate (holding plate 44A in FIG. 1) holds the substrate S by suction on the lower surface thereof.
[0104]
In this state, the coating head 19 is slid along the lower surface of the substrate S by a method similar to that of the coating apparatus in FIGS. The liquid is applied to the lower surface of the substrate S. During this time, a new substrate S is set on the upper holding plate (holding plate 44B in FIG. 1) by a substrate exchange device (not shown).
[0105]
When the application of the application liquid to the substrate S held by the holding plate 44A is completed, the rotation shaft 42 is rotated 180 degrees around the axis by the operation of a drive motor (not shown), and the holding plate 44A is turned upward and the holding plate 44B Is located on the lower side. Then, the coating liquid is similarly applied to the substrate S held by the holding plate 44B, and during this time, the substrate S held by the holding plate 44A and having been coated with the coating liquid is maintained horizontally by the substrate exchange device. It is removed from the holding plate 44A while being replaced, and is replaced with a new substrate S.
[0106]
As described above, also in the above-described coating apparatus, the coating liquid application process is performed alternately on the holding plate 44A side and the holding plate 44B side, and when the substrate S is replaced on the holding plate 44B, the holding process is performed. The application liquid is applied to the substrate S held on the plate 44A, and conversely, the application liquid is applied to the substrate S held on the holding plate 44B when the replacement of the substrate S is performed on the holding plate 44A. Therefore, the application liquid is always applied to the substrate S, whereby the application liquid is applied to twice the number of substrates S per unit time as compared with the conventional coating apparatus of FIG. It becomes possible to do.
[0107]
In the above-described coating apparatus, when adjusting the thickness of the layer of the coating liquid applied according to the type of the coating liquid, the head base 41 is rotated about the rotation center P ′ to obtain the desired inclination angle θ. And the rotation shaft 42 is also rotated about the rotation center P ′ to change the inclination angle. Then, the holder support arms 43A and 43B are rotated about the rotation center P 'with respect to the rotation shaft 42, and are adjusted to be horizontal when the holding plates 44A and 44B are positioned on the upper side. .
[0108]
When changing the angle of inclination between the head mount 41 and the rotary shaft 42, each of the rotary shafts is centered around the rotation center P 'so that the rotary angle of the rotary shaft 42 becomes half of the rotary angle of the head mount 41. By rotating, when the holding plates 44A and 44B are respectively positioned on the lower side, the setting can be performed such that the lower surface thereof is parallel to the sliding direction of the coating head 19.
[0109]
This is because, when the inclination angle of the rotation shaft 42 is changed by the angle α / 2, the angle between the holder support arms 43A, 43B and the rotation shaft 42 is also changed by α / 2, and the holding plates 44A, 44B are changed. When the holding plates 44A and 44B are positioned below the rotating shaft 42, the inclination angle thereof changes. This is because the angle α is twice as large as the variation of the inclination angle of
[0110]
【Example】
Next, the present invention will be described in more detail with reference to examples.
(Example 1)
Using the coating apparatus shown in FIGS. 1 and 2 and FIGS. 8 and 9, a glass substrate S for an LCD color filter having a width of 300 mm, a length of 350 mm and a plate thickness of 1.1 mm is prepared. A PVA aqueous solution having a viscosity of 5.0% and a viscosity of 5.0% was prepared.
[0111]
The coating head 19 has the shape and dimensions shown in FIGS. 3 to 6, respectively, and is set so that the relative angle between the coating head 19 and the substrate S is about 8 °. The moving speed of the coating head 19 was set to 30 mm / sec.
[0112]
Then, the coating liquid was applied to the substrates S held by the holding plates 17A and 17B and the holding plates 44A and 44B by the above-described steps. At this time, at the start of coating, the heights h1 and h2 (see FIG. 12) of the meniscuses L1 and L2 of the bead B formed between the coating head 19 and the substrate S are 0.5 mm and 0.7 mm, respectively. Set to.
[0113]
The substrate S coated with the coating liquid under the above conditions was dried in an oven at a temperature of 80 ° C. for 1 minute.
[0114]
As a result, the film thickness distribution of the coating film on the substrate S measured along the moving direction of the coating head 19 and the direction perpendicular to the moving direction is within any range of 260 mm × 300 mm of the coating surface of the coating liquid. Was 20000 ± 600 °, and good results could be obtained.
[0115]
The coating efficiency of the coating liquid on the substrate S at this time was 110 sheets / hour in the case of the coating apparatus in FIGS. 1 and 2, and was 100 sheets / hour in the case of the coating apparatus in FIGS. .
[0116]
The ratio of the height h2 of the meniscus L2 to the wet film thickness C2 (see FIG. 14) of the coating film Ra in the coating liquid application step was C2: h2 = 1: 350.
(Example 2)
A photoresist OFPR-800 having a solid content of 6.5% and a viscosity of 2.5 cps manufactured by Tokyo Ohka Kogyo Co., Ltd. was used in place of the coating solution of Example 1 as a coating solution, and the other conditions were the same as in Example 1. The application liquid was applied to the substrate S for each application device.
[0117]
As a result, the thickness distribution of the coating film measured along the moving direction of the substrate S and the direction perpendicular to the moving direction was 10,000 ± 300 ° in the range of 260 mm × 300 mm on the coating surface of the coating liquid. Yes, good results could be obtained.
[0118]
The coating efficiency of the coating liquid on the substrate S at this time was 110 sheets / hour in the case of the coating apparatus in FIGS. 1 and 2, and was 100 sheets / hour in the case of the coating apparatus in FIGS. .
[0119]
The ratio of the height h2 of the meniscus L2 to the wet thickness C2 (see FIG. 14) of the coating film Ra in the coating liquid application step was C2: h2 = 1: 350.
[0120]
【The invention's effect】
As described in detail above, according to the present invention, the coating liquid is applied by linearly sliding the coating head diagonally upward along the coating surface while facing the coating surface of the substrate. Even on the leaf substrate, a smooth and uniform coating film can be formed without being affected by the physical properties of the coating solution.
[0121]
Then, the step of applying the coating liquid to the substrate and the step of replacing the substrate coated with the coating liquid are performed alternately for each of the two sliders, so that the coating of the substrate by one coating head can be performed in a short time. The processing can be performed continuously without opening, so that the number of processed sheets per unit time can be increased.
[0122]
In addition, since the step of applying the coating liquid to the substrate and the step of replacing the substrate coated with the coating liquid are performed alternately on the pair of substrate holding members by rotation of the rotating shaft, the coating of the substrate by one coating head is performed. Can be continuously performed without any delay, and therefore, the number of processed sheets per unit time can be increased.
[Brief description of the drawings]
FIG. 1 is a side view showing an example of the best mode of the present invention.
FIG. 2 is a view of the example taken along the line II-II in FIG.
FIG. 3 is a perspective view showing an example of a coating head used in the example.
FIG. 4 is a front view of the coating head.
FIG. 5 is a plan view of the coating head.
FIG. 6 is a side view of the coating head.
FIG. 7 is a diagram showing a coating liquid supply mechanism used in the example.
FIG. 8 is a side view showing another example of the best mode of the present invention.
FIG. 9 is a view of the same example taken along line IX-IX in FIG.
FIG. 10 is a side view showing a conventional coating apparatus.
FIG. 11 is a schematic side view showing a relationship between a substrate and a bead at the start of coating in the conventional example.
FIG. 12 is an enlarged explanatory view showing a state of a bead at the start of coating in the conventional example.
FIG. 13 is a schematic side view showing the relationship between a substrate during coating and a bead in the conventional example.
FIG. 14 is an explanatory diagram showing an enlarged state of a bead during application in the same conventional example.
FIG. 15 is a schematic side view showing a relationship between a substrate and a bead at the end of coating in the conventional example.
[Explanation of symbols]
10 ... coating equipment
12… ball screw
13A, 13B ... slider
14. Linear guide (board guide member)
15A, 15B ... holder support shaft (substrate holding member)
16A, 16B: Holder support arm (substrate holding member)
17A, 17B ... holding plate (substrate holding member)
18 Ball screw
19… Coating head
19a ... Slit
21… Linear guide (coating head guide member)
40… Coating device
42… Rotary axis
43A, 43B: Holder support arm (substrate holding member)
44A, 44B ... holding plate (substrate holding member)
S: substrate

Claims (2)

A coating head having a band-shaped slit that opens upward and extends in the horizontal direction, and a substrate holding member that holds a substrate on which the coating liquid is to be applied in an inclined state above the coating head and in parallel with the coating head. The coating liquid is supplied to the coating head, a bead is formed between the coating head and the substrate held by the substrate holding member by the coating liquid discharged from the slit of the coating head, and the substrate and the coating are relatively formed. In a coating apparatus for applying a coating liquid to a substrate by moving the coating liquid on the substrate by moving the coating liquid in opposite directions, and applying the coating liquid to the coating liquid coating surface of the substrate from the beads.
The coating head is reciprocally movable along a coating head guide member that is inclined in a direction orthogonal to a strip-shaped slit extending in the horizontal direction of the coating head and in an upward direction,
Above the coating head guide member, a substrate guide member extending in a direction perpendicular to the coating head guide member and in the horizontal direction is arranged,
Two sliders are slidably attached to the substrate guide member along the substrate guide member, and the two sliders are alternately positioned above the coating head guide member,
A first position and a substrate where the substrate holding member positions the substrates respectively held by the two sliders such that the application liquid application surface thereof faces downward and is parallel to the moving direction of the application head; It is attached so as to be freely positioned at a second position where the coating liquid application surface is positioned upward and horizontal.
A coating device characterized by the above-mentioned. A coating head having a band-shaped slit that opens upward and extends in the horizontal direction, and a substrate holding member that holds a substrate on which the coating liquid is to be applied in an inclined state above the coating head and in parallel with the coating head. The coating liquid is supplied to the coating head, a bead is formed between the coating head and the substrate held by the substrate holding member by the coating liquid discharged from the slit of the coating head, and the substrate and the coating are relatively formed. In a coating apparatus for applying a coating liquid to a substrate by moving the coating liquid on the substrate by moving the coating liquid in opposite directions, and applying the coating liquid to the coating liquid coating surface of the substrate from the beads.
The coating head is reciprocally movable along a coating head guide member that is inclined in a direction orthogonal to a strip-shaped slit extending in the horizontal direction of the coating head and in an upward direction,
A rotating shaft that is inclined upward and rotatable around the axis is disposed above the coating head guide member,
A pair of the substrate holding members are attached to the rotating shaft so as to be symmetrical with respect to the rotating shaft, and hold when the respective substrate holding members are positioned above the rotating shaft with the rotation of the rotating shaft. Positioning the substrate in a horizontal state, positioning the substrate held when positioned below the rotation axis in a state parallel to the moving direction of the coating head,
A coating device characterized by the above-mentioned.

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